Brian is an evolutionary biologist. He received his PhD from Harvard University in the Department of Organismic and Evolutionary Biology where he studied plant genetics. Brian was a Kirschstein-NRSA postdoctoral fellow working with Marc Lipsitch and Bill Hanage at the Harvard T.H. Chan School of Public Health. As a postdoc, he studied bacterial evolution with a particular focus on modeling the evolution of multi-locus traits, such as antibiotic resistance, metabolic output, or antigen profile. While many bacterial pathogens frequently recombine, transferring small segments of DNA between individuals, some linkage (or statistical correlations) remains between mutations. Brian is interested in the consequences this residual linkage has on adaptive processes, since linkage between epistatically interacting loci may allow natural selection to spread beneficial mutation combinations. At CCDD he worked on many species but was particularly fascinated by N. gonorrhoeae, H. pylori, and S. pneumoniae.